reproduction is necessary to replace the organism and perpetuate the species
development and growth have evolved to allow the organism to reach maturity and reproduce
a progression of stages that lead from an undifferentiated state to a highly organized, specialized and mature state
development
an increase in size through the formation of enlargement of similar tissues types
growth (morphogensis)
an increase in the relative number of cells (mitosis)
plasia
an enlargement in the absolute size of cells (intracellular deposition)
trophy
When you lift the muscle cells undergo _____
Early embryonic development occurs by _____
trophy
plasia
growth episodes occur only intermittently
saltatory growth rate
episodes with no growth, or size increases
stasis growth rate
growth episodes occur constantly
continuous
an abnormal number of cells
Dysplasia
hyperplasia--
hypoplasia--
too many cells
too few cells
an abnormal cell size
dystrophy
occurs from conception through 8 weeks (trilaminar disc to 3 germ layers to primary palate development)
differentiation and development
8 weeks through 16 years of age
enlarge the structures, eventually stop
growth
8 weeks through death
ongoing process
remodeling
what are the 3 phases of craniofacial growth and development
differentiation and development
growth
remodeling
3 events of differentiation and development
germ layer differentiation and neurulation
neural crest cell formation, migration and differentiation
craniofacial development
when does craniofacial growth occur?
8-10 weeks through 16 years
what is bone remodeling
the process of bone resorption on one side (osteoclasts) and bone deposition on the other side (osteoblasts) that results in displacements
a rapid increase in growth velocity which restores the normal growth rate
"catch up" growth
True/False: growth may not always be "complete"
True
depends on timing, severity, and duration of insult
what is infancy driven by _____
nutrition
childhood driven by ____ ____ ____
adrenal growth hormones
adolescence drive to ___ ___ ___
gonadal growth hormones
brain case, houses brain, meninges, and CSF
forms intramembranously
Neurocranium
face, houses organs of the skull, dentition, and TMJ
forms intramembranously
viscerocranium
cranial base, platform for attachment of neurocranium and viscerocranium
forms endochondrally
chondocranium
True/ False: 90% of neuro- and chondrocranial growth completed by 7 years of age.
TRUE
True/False: 90% of viscerocranial growth completed by 10 years of age.
TRUE
three dimensional increases in various regions what are the regions
Chondrocranium
Viscerocranium
Neurocranium
what is a growth center
Areas that are genetic control and will grow on their own
what is a growth site
area that enlarge in response to something else and won't grow on their own
what are the two types of growth sites
Soft tissue growth sites
Osseous growth sites
what are the two types of growth centers
Soft tissue growth centers
Osseous growth centers
Regions that grow in response to intrinsic (genetic) factors and include the brain viscera, glandular tissue, sense receptors, nerves, blood vessels, and muscles
soft tissue growth centers
Regions that grow in response to intrinsic (genetic) factors
Regions that grow in response to extrinisic (epigenetic) factors and include muscle, epidermis, mucosal epithelium, blood vessels
soft tissue growth sites
Regions that grow in response to extrinisic (epigenetic) factors
Cortical bone surfaces, fibrous articulations (sutures)
osseous growth sites
4 principles of growth and remodeling
enlargement
displacement or translation
remodeling by cortical drift
remodeling by the "V" principle
an increase in size through resorptive and depository surfaces
enalrgement
a principle of growth and remodeling that consists of two parts
primary--the physical movement of whole regions by soft tissue growth
secondary--the physical movement of whole regions by the primary movement of the whole bones
displacement or translation
the relocation of bones through synchronous cortical remodeling
remodeling by cortical drift
the enlargement of bones through the cortical remodeling in a synchronous "V" wave
remodeling of the "V" principle
Variability in craniofacial morphology can be due to (5)
Sexual Dimorphism
Normal Population Variability
Genetic Factors
Pathology/Trauma
Cultural/Behavioral
True/False: males are roughly 92% size of females in human populations
FALSE
females are roughly 92% of males
True/False: Skeletal morphology and degree of sexual dimorphism varies with population and through time
true
True/False: you are not always able to assign a sex to every skull because some individuals may have a mixture of male/female features
true
True/False: Cannot assign sex to subadults
True
Methods are inaccurate, no better than flipping a coin!
Cranial index (width to length ratio)
>0.8
brachycephaly
Cranial index (width to length ratio)
between 0.75 and 0.8
mesocephaly
Cranial index (width to length ratio)
<0.075
dolichocephaly
Orthognathic occlusal
class I
Slightly-severely Retrognathic
class II
overbite
prognathic
class III
underbite
Sometimes mutations or disorders to cause the ____ to close prematurely—depending on which closes is what the shape of the head will be
sutures
most common craniosynostosis
sagital suture synostosis
4 Craniosynostosis Syndromes with FGFR Extracellular Mutations
Crouzon Syndrome
Apert Syndrome
Pfeiffer Syndrome
Jackson-Weiss Syndrome
Cranial vault deformity from abnormal ____ (____) forces.
postural
biomechanical
cultural factors that cause fronto-occipital modifications are due to
cradle boarding
intentional application of cord, textile, or head dress that produces a flattened forehead and posterior elongation of cranial vault bones
cultural factors--annular modifications
what controls craniofacial growth? (3)
Genetic factors
Functional factors
combination
What is harder to treat problems with genetic forces or functional?
genetic are much harder to treat because we have not figured out out to stop and start genes fluently yet while functional forces can be treated by appliances or distraction ontogensis
all bone and cartilage growth controlled by intrinsic (genetic) factors along articular surfaces
intrinsic growth centers (sicher)
all bone and cartilage growth controlled by extrinsic (epigenetic) soft tissue matrix growth and muscle function
functional matrix hypothesis (moss)
Functional matrices (5)
Neurocapsular matrix (Brain, meninges, CSF, and epicranial muscles)
Nasocapsular matrix (Nasorespiratory function through nasal mucosa)
